The invention relates to the field of sports which involve sliding. More specifically, it relates to a boot intended for snowboarding. It relates more particularly to the connection between the boot and the means which, on the boot, interact with the binding.
In a known manner, snowboarding boots can be, depending on the type of snowboarding practiced, either hard after the fashion of a ski boot, or soft. The invention relates in particular, but not exclusively, to this second family.
This type of boot generally comprises a flexible upper which is relatively deformable so as to allow leg movements and to be comfortable. This upper is associated with a sole assembly which comprises in particular an outsole which is relatively flexible and deformable so as to allow a good rolling movement of the foot during walking motion. This sole assembly also comprises means for interaction with complementary arrangements of the binding. These interaction means are anchored mechanically in this sole assembly and in particular in a reinforcing piece associated with the sole.
A great many types of interaction means exist, the geometry and the design of which depend on the type of binding used. Thus, some bindings interact with the boot in the region of a spindle or a transverse plate which protrudes on each side of the boot. In other standards, the binding interacts with inserts located on both sides of the sole. In systems which are different again, the binding can comprise jaws which render captive a projection located under the sole of the boot.
The sole assembly, and in particular the reinforcing piece in which the means for interaction with the binding are anchored, clearly depends on the nature of these means. This reinforcing piece can be located inside the boot, above the outsole, and take the form of a frame receiving the foot. This reinforcing piece can also have smaller dimensions and form a plate which can, if appropriate, be embedded inside the outsole, or accommodated in a housing provided for this purpose in the outsole.
This anchorage creates a rigid mechanical connection allowing the effective transmission of forces from the foot of the user to the snowboard. The interaction means of the boot and the binding are attached at at least two points or two contact zones, so that the boot is completely mechanically integrated with the board when the binding is engaged. This integration makes possible very good transmission of the forces necessary for steering. However, this firm, permanent attachment prevents lateral deflection movements of the boot. It is of course known that in certain types of snowboarding, in particular freestyle, the position of the user changes continuously in relation to the board and the inclination of the leg is consequently adjusted. The firm, permanent attachment of the boot to the board therefore limits the possibilities of inclination of the leg, and therefore the suitability of the board for freestyle snowboarding.
One problem which the invention therefore aims to solve is that of facilitating lateral inclination of the leg while ensuring effective, rigid attachment of the boot to the binding.
Analyzed more specifically, the behavior sought is that observed with a strap binding, the foot being capable of orienting itself inside the binding following a rolling motion resulting from the deformation of the sole assembly combined with pivoting. This allows the foot to receive the sensations originating from the board over a relatively large surface area. In other words, it is important that this rolling motion of the foot does not take place to the detriment of the ease of attachment of the boot to the binding.
In other words, another problem which the invention seeks to solve is that of reconciling the rolling motion capacity with a firm, easy attachment of the boot to the binding of automatic type.
A number of solutions have already been proposed to afford a degree of freedom to the connection between the boot and the board.
Thus, document U.S. Pat. No. 5,971,419 describes a binding comprising two elements, namely a baseplate integrated with the binding and a platform mounted on this baseplate. This platform is connected to the baseplate via a longitudinal articulation spindle allowing lateral deflections of the platform, and therefore of the boot which it receives. This binding has numerous disadvantages. In fact, owing to its design, this binding functions only for hard boots. Furthermore, only that portion of the sole of the foot located vertically in relation to the articulation spindle can exert bearing forces, which results in a loss of sensation. Moreover, this binding holds the foot relatively far from the board. More specifically, the boot pivots about an axis which is located under the sole. For optimum performance, however, it is desirable rather to maintain permanent bearing.
A similar solution is described in document DE-U-88 15173.5. Such a device includes, between the baseplate and the pivoting platform, a layer of compressible material providing damping of the lateral deflection. This solution has the major disadvantage of requiring a large number of mechanical pieces which increase the cost of the binding and the risks of mechanical failure. Moreover, such a binding is not arranged so as to hold the boot captively by automatic fitting of the boot into the binding, but on the contrary requires manual actions on the part of the user.
Document FR 2 734 167 also contains a proposal for a binding of a particular type which interacts with the boot on only one side of the latter. In this way, the boot has a capacity for relative movement in relation to the board about an orientation axis lying in the longitudinal direction of the boot. Owing to its asymmetry, this device favors the transmission of forces on only one side of the boot, which is a handicap for certain types of snowboarding. Moreover, in order to avoid that side of the boot which is not integrated with the board lifting excessively, it is necessary for the sole to be sufficiently rigid, which compromises walking comfort.
Finally, as the attachment in relation to the binding is effected on only one side of the boot, the mechanical stresses exerted in the region of such an attachment are particularly great, which increases the risks of the means for interaction with the binding being pulled out.
Furthermore, document WO 97/27773 describes a snowboarding boot, the sole of which comprises means for interaction with the binding consisting of two spindles located along the longitudinal median plane of the boot. These longitudinal spindles are held captively by complementary jaws of the binding. The peripheral zone of the sole of this boot consists of compressible material. Thus, when the user wishes to tilt his leg laterally, the sole pivots about the spindles for interaction with the binding, and the compressible zone is crushed. This boot has the disadvantage of exposing the compressible zone to contact with the ground when the boot is used for walking. This results in accelerated wear of this compressible zone which is made of a material which is not very resistant to abrasion. After wear of this material, the boot no longer bears laterally on the board, and therefore pivots freely in relation to the longitudinal spindles, thus inducing a sensation of instability. Moreover, the lateral deflection capacity of such a boot is difficult to regulate, as it depends virtually exclusively on the thickness of the compressible peripheral zone.
A problem which the invention aims to solve is that of allowing lateral deflection of the boot in relation to the binding or a possibility of rolling while providing firm, effective holding of the boot in relation to the board, and while allowing automatic fitting of the boot into the binding.
The invention therefore relates to a snowboarding boot which comprises:
a sole assembly comprising in particular:
an outsole, the lower face of which is intended to come into contact with the ground;
a reinforcing piece;
means for interaction with complementary arrangements of the binding, said means being mechanically integrated with the sole assembly.
This boot is characterized in that it comprises an element made of a material having elastic properties interposed between the interaction means and the sole assembly, said element being capable of being deformed in order to allow lateral deflection or a rolling motion of the boot in relation to the binding.
In other words, the means for interaction with the binding are connected to the rigid part of the boot by an elastic connection which allows slight relative displacement of these means in relation to the boot, and therefore of the boot in relation to the binding and the board. Thus, while maintaining firm, permanent attachment of the boot to the binding, the user benefits from an additional degree of freedom allowing the rolling motion of the boot in relation to the binding. This additional degree of freedom is afforded by the structure itself of the boot, in contrast to the systems of the prior art, in which any degrees of freedom result from the configuration of the interface between the boot and the binding.
In practice, the deformation of the elastic element takes place by compression or tension in a vertical direction, and by shear in a horizontal plane. The combination of these two deformations of different type makes it possible to obtain the rolling motion sought, which is favorable for good perception of sensations. By an abuse of language, this movement is described as xe2x80x9crollingxe2x80x9d. This motion results in a different vertical displacement of the two lateral ridges of the boot, possibly with a slight transverse translation.
In practice, the means for interaction with the binding can advantageously be anchored in the reinforcing piece.
According to the design of the interaction means, the elastic element can consist either of a zone of the outsole or of a supplementary element interposed between the sole assembly and the interaction means.
Thus, in the first case, the means for interaction with the binding are positioned in a recess of the sole, and that portion of the sole comprised between the reinforcing piece and the interaction means serves as an elastic element. The outsole then has sufficient flexibility to be deformed under the action of the forces exerted by the user.
In the second case, the interaction means are positioned under an additional element which is itself arranged under or on the sides of the outsole.
According to another characteristic of the invention, the boot can moreover comprise means capable of limiting the displacement of the interaction means in relation to the sole assembly.
In other words, the amplitude of movements of the interaction means is limited, which proves to be useful during fitting of the boot into the binding. In fact, when the user engages his boot in the binding, he exerts a downwardly oriented vertical force which tends to deform the elastic element. If this elastic element is deformed excessively, the engagement of the interaction means in the complementary arrangements of the binding could prove to be difficult or even impossible in some cases. Thus, in certain geometries, the means of limiting the displacement of the interaction means allow optimum, automatic fitting of the boot into the binding.
By selecting an elastic element made of a number of materials, it is possible to favor the deformations of the element in certain directions. The compression or the stretching of the elastic element is therefore different from one side to the other of the boot. Thus, when the elastic element is asymmetric, deflection of the boot on one side of the boot is facilitated in relation to the other.
It is likewise possible to bring about asymmetric behavior by adapting the geometry of the different means of the boot. Thus, it is possible to provide travel limiters which are different from one side to the other of the boot. These limiters can advantageously be adjustable. Deflection on one side of the boot is thus favored in relation to the other.
According to another characteristic of the invention, the boot can likewise comprise means which are capable of bringing about pivoting of the interaction means in relation to the reinforcing piece. In other words, deformation of the elastic element is favored in a specific direction, and in particular that which leads to lateral inclination of the leg. Thus, the elastic element is forced to be deformed depending on the pivoting movement of the interaction means. Moreover, the pivoting means bring about direct transmission of the forces exerted vertically which are not intended to induce an inclination of the leg. With regard to these forces, it is thus possible to avoid stressing the elastic element.
In practice, the element interposed between the reinforcing piece and the interaction means can advantageously have viscoelastic properties making it possible to favor slow deformations while remaining snappy at the time of rapid deformations. Moreover, this element thus absorbs some of the vibrations being transmitted from the board in the direction of the remainder of the boot.
As mentioned already, a great many types of interaction means exist, very many of which can be used for a boot according to the invention.
Thus, in a first family of variants, the interaction means can comprise a transverse spindle, the ends of which are intended to be held captively by jaws of the binding. In this case, the boot can comprise a plate covering the transverse spindle to hold the transverse spindle under the outsole. In this case, the plate is integrated with the reinforcing piece by connection means.
In practice, the plate can advantageously slide in relation to these connection means so as to allow, but also to limit, the displacement of the interaction means in relation to the reinforcing piece and therefore the bottom of the outsole.
In order to allow pivoting of the boot in relation to the transverse spindle, said spindle can comprise an enlargement which comes into contact with the plate, thus allowing the spindle to pivot in relation to the plate and therefore in relation to the reinforcing element.
The boot according to the invention can comprise another type of interaction means consisting of a transverse plate, the ends of which are intended to be held captively by the binding.
Advantageously, the boot can then comprise connection means extending through the plate, which are anchored in the reinforcing piece and which thus allow the plate to slide in relation to the connection means. This plate can be displaced in relation to the reinforcing piece according to different modes of operation. Thus, under the action of a force exerted downwardly, the material interposed between the plate and the outsole works under compression. On the other hand, under the action of a force exerted upwardly, this same material works under tension.
The invention can also be adapted to another type of interaction means, which means comprise two inserts forming a cavity, which are each arranged on one side of the boot and are intended to receive arrangements of the binding, each insert being accommodated in a housing formed in the element made of a material having elastic properties, said element itself being accommodated in the outsole.
In this case, the binding comprises levers, a part of which comes to be received in the inserts on each side of the boot. These inserts are mounted inside the thickness of the outsole and are connected to the latter by the characteristic elastic element. These inserts therefore have a certain capacity for displacement inside the elastic element, which therefore allows lateral deflection of the boot.
In practice, the elastic element can itself advantageously be accommodated in a seat which is itself integrated with the reinforcing piece. In this case, the two seats, each receiving a lateral insert, are integrated with one another, which makes it possible to avoid excessive deformation of the sole and to improve the stability and the interaction with the binding.
The boots according to the invention can also receive another type of interaction means consisting of a projection located under the sole and intended to be held captively by arrangements of the binding, such as jaws. In this case, the projection can be, for example, mounted directly in a recess under the sole, which comprises directly in line with the projection a zone made of elastic material constituting the characteristic elastic connection. The boot can likewise receive a complete elastic projection which is positioned in a housing under the sole between the outsole and the characteristic projection.
Advantageously, it is possible to provide connection means extending through the projection and anchored in the reinforcing piece while passing through the element made of material having elastic properties so as to allow sliding of the projection in relation to the connection means.
The invention is not limited only to the types of interaction means described above but also covers solutions in which the binding interacts with the boot in the region of a number of points on each side of the boot. It is thus possible to provide two (or more) spindles or transverse plates, or two (or more) lateral inserts on each side of the boot.